Private investigator Anthony Pellicano, who is acting as his own attorney in his federal wiretapping case, says he may cause some fidgeting in the witness stand if any of his former Hollywood A-list clients decide to testify against him.

Jury selection began yesterday in a case that has Hollywood's power players nervous about who else might be charged and what secrets might be exposed.

Since his indictment more than two years ago, the crafty, private eye has refused to divulge sensitive information about his rich and famous clients.

Mr Pellicano said he will not violate anyone's confidence but that celebrities who testify against him could face a rough time during cross-examination.

"I'm not going to willfully hurt anyone," Mr Pellicano told The Associated Press during a recent telephone interview from federal prison in Los Angeles. "But I might ask questions... that might make people uncomfortable."

In court documents filed on Friday, federal prosecutors laid out much of their trial strategy. They portrayed Mr Pellicano, 63, as an ambitious investigator-to-the-stars who ran a criminal enterprise that included wiretapping phones and bribing police and telephone workers to get the "gold standard" of confidential information for his clients.

He is accused of charging at least $25,000 (£12,500) for dirt that could be used to gain an edge in divorce and business disputes. Some of the information even involved rape and murder cases, according to the court documents.

Prosecutors estimate that Pellicano, retired Los Angeles police sergeant Mark Arneson and former telephone company employee Rayford Earl Turner collected nearly $2m from what authorities called a racketeering scheme. For the most part, however, prosecutors failed to determine that Mr Pellicano's clients were aware of the illegal methods he used.

Prosecutors have said those targeted included Sylvester Stallone and the comedians Garry Shandling and Kevin Nealon.

It was unclear whether any of them would testify since prosecutors won't file a list of possible witnesses until the trial begins. Stallone told reporters last month that he would be willing to testify, even though he had not yet been subpoenaed.

Despite having a treasure trove of Hollywood secrets, Mr Pellicano said he will not reveal them.

"There are a lot of celebrities' secrets I still hold and I haven't broken a vow, even to the people I don't like," he said. "If I was going to say something, I would have said something a long time ago."